tyre pressure

[patonga]

Simple question. What's best?

[dale_1]

pressures

I usually run what my steering head says, and as long as I dont dump the throttle in a turn it is wonderful. Bridgestone Spitfire S-11s front and rear at 28 frt 40 rear.

The sides grip great and the centers feel smooth.

10 grand outta the rear and 20 outta the front. Average unless I smoke em alot.

[Jerry]

Uh....there is no "best"; depends on the tires you run, equipment you carry, how much you weigh, any suspension mods, and so on.

I run Dunlop Elite IIs on a full-dress XJ (fairing and saddlebags) and weigh about 260. Tire pressure is 40 psi rear, 36 psi front. Have played with other settings, 40 in the back seems OK but can go down to 32 psi front if I want slightly softer ride. (Progressive brand fork springs have replaced the stock fork springs, no air pressure used in the forks.) Rear air shocks running 26 - 28 psi seem to be about the best for me, I can vary that instead of tire pressure to modify ride characteristics.

Note: the XJ came stock with air-adjustable forks and rear shocks, as did the '81H, I think....

[79XS11F]

What's "best" will usually be the bike manufacturers specs that are in the manual or a label somewhere on the frame. Those specs hold even if different tires are used so long as the tire specs are within the manuals range. The number the manual suggests is best for all round normal use for the bike.
Different riding styles, weight loads, suspension settings and suspension condition will of course affect what's "best" for you. So it's really something that only you can determine. Start with whats in the manual and go from there. It's a common mistake with tires to inflate them to what's stamped on the tire when they should be inflated to whats on the bike or car labels.
Rob

[TADracer]

I think that the correct tire pressure is a matter of feel provided you are not too excessively low or high. I run 35 rear, 30 front and find that to be the the spot for best handling in my particular case. I like the term 'sweet spot' and use it often. Tires have a sweet spot too and it is a hell of a lot easier to hit than say, carb jetting. So try adjusting till you get it right.

[Snow]

For me and my nekkid standard, anything over 29 makes the front end bouncy on rough roads.

[HobbyMan]

I thought the pressure rated on the tire was the MAX allowable. Correct me if I am wrong. Many times what is posted on the vehicle is lower. I usually vary between the two. On my excursion, the door sticker says around 60 something. On the tire, they are rated around 75. At 60 they look deflated and that makes for wobbly towing. We run them max when towing. Same story with our bias ply pickup truck tires. I wish my excurison had bias plys but that is another story.

[79XS11F]

That's right .. Pressure on the side wall of the tire is the MAX pressure for that tire. The pressure listed on the vehicle is for the tires that came with the vehicle. Any similar tire put on that vehicle should delver its best all round performance at that same vehicle listed pressure. The designers of the vehicle selected the tires that come with the vehicle based on the intended use, MAX expected loads, etc , etc. The pressure listed on the vehicle for the "stock" tires is part of the whole calculation that will deliver the ride intended.
Rob

[Jerry]

Not quite correct; the Max pressure is where the tire reaches its maximum load carrying capability; inflating the tire past the max pressure will not increase carrying load. However, for every pound of pressure under max you loose some load capacity, 4psi = 60 to 70 lbs according to the Dunlop site.

Here is another quote from Dunlop about general tire pressure to use on touring bikes:

************
For touring motorcycle loading, follow these general guidelines:
Light loads-single rider with some luggage (up to 200 lb. total)-minimum tire pressure of 32 psi front and 36 psi rear must be maintained.
Heavier loads-dual riding and/or luggage (from 200 lb. total up to maximum motorcycle capacity stated in the owner's manual)-pressure of 36 psi front and 40 psi rear must be maintained.
Please Note:
For any dual riding or fully loaded use, 40 psi must be maintained in all Dunlop rear tires fitted to touring motorcycles.
**************

On the Dunlop fitment guide for the Elite III, the generic recommended starting points are 32 psi rear and 30 front. Therefore, the "correct" tire pressure will generally be between 30 - 36 psi front and 32 - 40 psi rear, at least for Dunlop products.

Remember, the XS - XJ 11s are heavy bikes riding on narrow tires. I would reccomend starting at higher pressures and working your way down until you get the 'feel' you like best.

Debate can be made if our bikes are 'touring' or 'sport', but for tires and pressure settings the 'touring' classification seems a better fit.

[jetmechmarty]

Dunlop recommends

It's been a while since I looked, but I remember seeing Dunlops recommended tire pressure for my bike matched what the owner's manual reads. I'm running their GT501 tires at standard pressure or as per the owner's manual. IIRC, the max pressure on the sidewall is considerably higher.